Dialkylaminocinnamates and dialkylbenzalmalonates in ultraviolet absorbing compositios and methods



June 25. 1968 J, BAKER ET AL 3,390,051

DIALKYLAMINOCINNAMATES AND DIALKYLBENZALMALONATES IN ULTRAVIOLETABSORBING COMPOSITIONS AND METHODS Filed March 31, 1964 09 I 0-8 ffWAVELENGTH m u United States Patent 3,390,051 DIALKYLAMINOCINNAMATES ANDDIALKYL- BENZALMALONATES IN ULTRAVIOLET AB- SORBING COMPOSITIONS ANDMETHODS James Albert Baker, Farnham Royal, John William James,

Langley, and Harry Polkinhorne, Wokingham, England, assignors toAspro-Nicholas Limited, a British company Filed Mar. 31, 1964,'Ser. No.356,159 Claims priority, application Great Britain, Apr. 3, 1963,13,124/63 14 Claims. (Cl. 167-90) This invention relates to ultravioletabsorbing compositions and is particularly, but not exclusively,concerned with cosmetic sun-screening compositions for topicalapplication to the skin.

It is known that in the case of normal light-skinned persons, it is notthe whole of the ultraviolet portion of the radiation of the sun thatcauses erythema or burning; it is that portion of the ultravioletradiation of a wavelength between about 280 or 290 m and about 320 Ill1, which is responsible for the distressing burning suffered by normalwhite persons exposing their skin to strong and/ or prolonged sunlight,whilst ultraviolet radiation of longer wavelengths up to about 400 or420 mp. causes tanning, namely a brownish or golden coloration of theskin which is usually aesthetically acceptable, as opposed to theunsightly reddish coloration denoting burning, which is usuallyaccompanied by discomfort or pain.

It is widely desired to secure tanning of the skin as by sunbathing forpurposes of health and/or appearance and to enable or aid persons tosubject themselves to the tanning process while avoiding or diminishingthe discomfort and even dangers of erythema, there have been madeavailable so-called sunscreening compositions, usually in the form ofcreams or lotions, for topical application, which sunscreeningcompositions are adapted to or intended to form, deposit or leave on thesurface of the skin after application a film comprising a sunscreeningagent which will absorb at least the bulk of that portion of theradiation of the sun of a Wavelength between about 290 and 320 m whilepermitting the passage of at least the bulk of that portion of theultraviolet range of a wavelength exceeding about 320 m whereby tanning(as opposed to burning) of the subject will not be substantiallyhindered.

It is, however, the case that a proportion of persons diifer from thenorm, particularly persons suffering from certain illnesses such asphotophobia or types of dermatitis, in having skins which are subject toburning not only by ultraviolet radiation of wavelengths between 290 and320 m but also by other ranges of ultraviolet radiation from 320 m up to400 or even 420 m The use of conventional sunscreening compositionsintended to permit or facilitate tanning will not enable such persons tosunbathe or otherwise expose themselves to the sun with comfort andsafety since such compositions will not provide a film which will filterout the ultraviolet radiation of longer wavelengths.

It is an object of the present invention to provide a cosmeticsunscreening composition appropriate for topical use by persons liableto sufler erytherna on exposure to ultraviolet radiaton of a wavelengthexceeding 320 m According to one aspect of the present invention, anultraviolet absorbing composition for topical application comprises adermatologically acceptable liquid or semi- 3,390,951 Patented June 25,1968 liquid carrier having dissolved or dispersed therein a proportionof at least one dermatologically acceptable compound represented by thegeneral formula:

OOY

wherein W represents hydrogen or a COZ group; Y and Z, which may be thesame or different, each represent an alkyl group, on 0R group, where Rrepresents hydrogen or an alkyl or alkoxyalkyl group, or an OB group,where B represents a dermatologically acceptable cationic group; and Rand R which may be the same or different, each represent hydrogen or analkyl or aralkyl group, for example benzyl, or R and R together represent a straight or branched chain alkylene group, optional- 1yinterrupted by a hetero atom, for example a pyrrolidino, piperidino,morpholino or piperazino group. It is preferred to employ a compound ofFormula I in which W represents hydrogen and in which Y is representedby 0R where R is an alkyl group containing from one to four carbonatoms, such as methyl, ethyl, n-propyl or isobutyl.

When W in Formula I represents a COZ group, it is preferred that atleast one, and advantageously both, of Y and Z is represented by 0Rwhere R is an alkyl group containing from one to four carbon atoms, suchas methyl, ethyl, n-propyl or n-butyl, or a lower alkoxyalkyl group,such as one having the general formula -C H OC H wherein x and yrepresent integers totalling at least 3, and preferably from 4 to 6,-for example methoxypropyl, ethoxyethyl, n-butoxyethyl or methoxybutyl.

When Y and/ or Z in Formula I represents OB, B may be, for example, analkali metal, such as sodium or potassium, or an ammonium group, or anacceptable substituted ammonium group, such astrishydroxyethylarnmonium.

In the preferred compounds, advantageously R and R both represent alkylgroups having from 1 to 4 carbon atoms, such as methyl, ethyl, n-propylor n-butyl, and most advantageously one or two carbon atoms.

The group is preferably attached to the benzene ring in the paraposition.

The especially preferred class of compounds for use in accordance withthe present invention is that having the general structural formula:

wherein R and R which may be the same or different, each represent analkyl group having from one to four and most advantageously one or twocarbon atoms, and Y represents an 0R group, where R, is an alkyl grouphaving from one to four and most advantageously two or four carbonatoms.

A specific example of a compound falling within the difinition ofFormula II and hence illustrative of the compounds which may be used inthe compositions of the present invention is isobutylp-dimethylamino-cinnamate, which has the structural formula:

COY

COZ

wherein R and R which may be the same or different, each represent analkyl group having from one to four and most advantageously one or twocarbon atoms, and Y and Z, which may be the same or different, eachrepresent an R group, where R is an alkyl group having from one to fourand most advantageously one or two carbon atoms. A specific example of acompound of the foregoing class is diethylp-dimethylamino-benzalmalonate.

The substituted malonates for use in accordance with the presentinvention may be made by condensing an appropriate aminobenzaldehydewith an appropriate ester of malonic acid, for example by heating thereactants (conveniently under reflux with provision for the separa tionof formed water) in solution in a mutual solvent in the presence of atleast one condensation catalyst, for example piperidine. If the desiredend product is an acid or a salt, the ester may be carefully hydrolysedunder alkaline conditions, the acid liberated, and, for a salt,neutralized with the appropriate base. If the desired end productcontains a primary amino group, that is if R =R =H, the group must beprotected during the course of the condensation by an appropriateprotecting group such as acetyl, which is removed by appropriate meansat the end of the reaction.

The substituted cinnamates for use in accordance with the presentinvention may be made by condensing an appropriate aminobenzaldehydewith an appropriate ester of acetic acid in a mutual solvent(conveniently an excess of the ester), in the presence of a condensationcatalyst, for example sodium metal or sodium hydride. If the desired endproduct is an acid it may be obtained by hydrolysis of the ester, but isbetter obtained by condensation of the appropriate aminobenzaldehydewith malonic acid in a mutual solvent in the presence of a condensationcatalyst such as piperidine. If the desired end product is a salt it maybe obtained by neutralisation of the acid with an appropriate base. Ifthe desired end product contains a primary amino group, the group mustbe protected during the course of the condensation by an appropriateprotecting group, such as acetyl, which is removed by appropriate meansat the end of the reaction.

Insofar as is presently known, all but three of the compounds fallingwithin the definition of Formula I are novel compounds. Thus accordingto another aspect of the present invention, there are provided novelcompounds represented by Formula I above, the values of W, Y, R and Rbeing chosen so that when R and R are both methyl and the group.

4 is in the para position, W is not hydrogen when Y is a hydroxy orethoxy group and W is not a carbethoXy group when Y is an ethoxy group.

It has been found that compounds falling within the definition ofFormulae I and II absorb ultraviolet radiation strongly at wavelengthsexceeding the range of about 290 to 320 m conventionally regarded as theburning range and give a useful measure of absorption up to about 400 mand that these compounds may be formulated with a dermatologicallyacceptable liquid or semiliquid carrier, for example in the form of acream or lotion, to provide a composition which on topical applicationwill constitute or leave on the skin a film or coating which will absorbat least a substantial proportion of ultraviolet light falling upon itand so prevent or diminish burning even in the case of persons liable tosuffer burning from irradiation within wavelengths exceeding about 320nm and extending up to about 400 or even 420 II'l/L.

Novel sunscreening compositions such as cosmetic oils, alcoholicsolutions, lotions, lipsticks, ornaments, creams and other emulsifiedproducts may be prepared with the compounds proposed according to thisinvention. These compositions may be formulated as cosmetic preparationsin otherwise conventional fashion. It is preferred that the should benot only dermatologically but also cosmetically or aestheticallyacceptable.

Depending on the degree of protection desired and on the vehicleemployed, satisfactory results may be obtained with compositionscontaining from 0.5 to 10% by weight of the compounds of this invention.Preferably from 0.9 to 3% by weight and most advantageously from 1 to 3%by weight is employed although larger amounts may be used if desired.The optimum proportion to employ will depend particularly on the natureof the coating or film formed or left on the skin, since some types offormulation will permit of the formation of a screen of a greaterconcentration of screening agent per unit of area than others, dependingfor example on viscosity, spreading power, and the permanence orotherwise of the vehicle or constituents thereof.

The novel sunscreening compositions of this invention are not confinedto any particular classes of cosmetics or to any particularformulations. Nevertheless, it is preferred to employ the novelcompounds of this invention along with a substantially greater amount ofa dermatologically acceptable vehicle compatible with the skin, such ascorn oil, aqueous ethanol, isopropanol, sesame oil, propylene glycol,benzyl alcohol, oleyl alcohol, isopropyl esters of fatty acids, such asmyristic and palmitic acids, or a mineral oil or wax. The vehicle shouldbe of such a viscosity and/or wetting power that the composition may besatisfactorily applied to the skin as a continuous film or coating,despite the natural oilness thereof.

The novel sunscreening compositions are applied to the skin in known andconventional manner, normally just prior to the user exposing himself orherself, as the case may be, to the rays of the sun. at least onecompound falling within the definition of the present invention, anultraviolet absorbing composition comprises a dermatologicallyacceptable liquid or semi-liquid carrier having dissolved or dispersedtherein at least one compound falling within the definition of Formula Iabove and also at least one other dermatologically acceptableultraviolet absorbing compound, whereby the combined effect of theplurality of ultraviolet absorbing compounds enhances the totalultraviolet absorbing properties of films or coatings resulting from orformed by the application of the composition to the skin.

The second compound is advantageously one whose ultraviolet absorptionis complementary to that of the first ultraviolet absorbing compoundwhereby the extent of the range and/ or the extent of the amount ofultraviolet radiation absorbed by the film or coating is increased.

Advantageously, the first compound shall exert its maximum absorption ofultraviolet light at a wavelength between 320 and 400 mg and the secondcompound shall exert its maximum absorption thereof at a wavelengthbetween 290 and 320 mg.

The composition according to this feature of the invention may containthe two compounds in a combined amount of from 0.5 to 10% by weight, andmost advantageously from 0.9 to by weight, of the total weight of thecomposition. The molar ratio of the two compounds one to the other maybe from 1:10 to :1, preferably from 5:1 to 1:5 and most advantageouslyfrom 2:1 to 1:2.

It is preferred that the two compounds and the ratio in which they areemployed are such that a 0.5% solution of the compounds (taken in thatratio) in a solvent transparent to ultraviolet radiation (for exampleethanol) in a layer 1 cm. thick shall reduce the intensity of allradiation between the wavelengths 290 and 400 mp. which passes into itby at least 90%.

Examples of sunscreening compounds which may be used as the secondultraviolet absorbing component of a composition according to theinvention are isobutyl dimethylaminobenzoate, menthyl salicylate andethoxyethyl and other lower alkoxyalkyl p-methoxycinnamates,particularly such as have at least four, and preferably from four to sixcarbon atoms, in the alkoxyalkyl group, such as 2-ethoxyethylp-methoxy-cinnamate. Other suitable sunscreening compounds may, however,be employed, the second such component advantageously being one adaptedto absorb in the erythematogenic range as it is normally understood, socomplementing the absorption in the tanning range (as it is normallyunderstood) provided by the first component.

A difficulty frequently experienced in formulating topical sunscreeningcompositions is that of securing the presence in an acceptable base orvehicle of a sufiiciently high concentration of the screening agent toprovide after application a film or coating the screening contact orpower of which will be sufficient to achieve the desired purpose. Thisis because of the quite limited solubility of many otherwise acceptablescreening agents in carrier bases which are acceptable on dermatologicaland cosmetic grounds. The present invention in providing in accordancewith one embodiment thereof compositions containing at least twodistinct screening agents tends to obviate this difficulty to the extentthat each agent has its own solubility in the base employed, thuspermitting a total concentration of the two agents greater than thatwhich might be obtainable with a single agent, whereby the overallultraviolet absorption eiiect resulting from the use of the compositionsis enhanced not only in the sense that the absorption spectra of the twocompounds is complementary, but also to the extent that the ultravioletabsorption spectra of the two compounds so far as they overlapsupplements one another.

The foregoing advantage of compositions containing at least two distinctscreening agents in accordance with one embodiment of the invention isillustrated more clearly in the accompanying drawing which shows ingraphic form the ultraviolet absorption of three blackout lotions, thespectra of which were obtained from smears of lotion formulations of thesunscreening agents in a lotion base on silica plates, without drying.Curve 1 was obtained from a lotion containing 1.5% by weight of theknown screening agent 2-ethoxyethyl p-methoxy-cinnamate; curve 2 wasobtained from a lotion containing 1.5 by weight of a novel screeningagentin accordance with the invention, namely isobutylp-dimethylamino-cinnamate; and curve 3 was obtained from a lotioncontaining 1.5 by weight of each of the screening agents used in thelotions relating to curves 1 and 2. The curves have been adjusted tocompensate for variations in thickness between the three smears.

The lotion base used in formulating the lotions incorporating thescreening agents was as follows:

The present invention also provides as a further aspect thereof a methodof protecting the skin against erythemaproducing or other undesiredultraviolet radiation, which comprises applying to the skin a film orcoating of a composition comprising a cosmetic carrier havingdisseminated therethrough an effective proportion of one or moreultraviolet absorbing compounds represented by Formula I. The inventionis not limited to the protection of the person or parts thereof againsterythematogenic radiation since, for example, the invention also findsapplication in the protection against tanning of normal white persons,such as those who may wish to remain wholly or in part untanned despiteexposure to tanning radiation, such as on the grounds of appearance. Inthis connection it is contemplated that the invention will findapplication in those cases where the extent of clothing of the personwill vary from time to time and it is desired to avoid the appearance ofvisible marking as to the extent of dress or undress on a previousoccasion under tanning conditions.

The invention still further provides a concentrate compositioncontaining at least two ultraviolet absorbing compounds as describedabove which may be employed in the manufacture of topically applicablecompositions according to the invention by incorporation in a suitableproportion in a dermatologically acceptable liquid or semi-liquidcarrier. A concentrate composition according to the invention mayconsist only of the two or more compounds to the extent that they arecompatible and/ or the concentrate composition may additionally comprisean extender or diluent material which may ultimately form a component ofthe ultraviolet absorbing composition or which is more or less readilyseparable from the mixture of compounds prior to or'on incorporation inthe eventual composition, as by evaporation.

The expression dermatologically acceptable" is used herein to indicatenot only that the material or compound referred to is acceptable onstrictly dermatological grounds, but also that it is acceptable on otherphysiological grounds, that is to say that if, for example, the materialor compound is absorbed through the skin into the blood-stream, it shallnot be toxic in the amounts and by the route it is absorbed.

The following examples are illustrative of the invention. Examples 1 to6 illustrate the preparation of ultraviolet absorbing compounds whichmay be used in formulating ultraviolet absorbing compositions inaccordance with the invention and Examples 7 to 10 illustratecompositions in accordance with the invention.

EXAMPLE 1 Diethyl p-dimethylamino-benzalmalonate A solution ofp-dimethylamino-benzaldehyde (10.5 g.), piperidine (1 m1.), benzoic acid(0.3 g.) and ethyl malonate (9.4 ml.) in dry benzene (20 ml.) was heatedunder reflux at 140 C. until no more water could be separated out fromthe refluxing distillate by means of a Dean & Starke phase separatorassociated with the reflux column. On cooling the desired compoundcrystallized. Yield (on recrystallization from aqueous ethanol) 14 g. ofpale yellow crystals, M.P. Ill-112 C., solubility in water (20 C.)(0.1%, Amax. 370 mu, molecular extinction coeflficient=33,000.

7 EXAMPLE 2 p-Dimethylamino-cinnamic acid p-Dimethylamino-benzaldehyde(50 g.) and malonic acid (35 g.) were heated in pyridine (250 ml.) andpiperidine ml.) on the steam bath for twelve hours. The reaction mixturewas then poured into a mixture of crushed ice (1 kg.) and glacial aceticacid (500 ml.) with stirring. The resulting product was collected,washed with dilute acetic acid and water. After drying it wascrystallized from ethanol to give the desired compound. Yield 39 g. of ayellow solid, M.P. 227232 C. (with decompositon).

EXAMPLE 3 Ethyl p-dimethylamino-cinnamate Sodium hydride (7 g. of a 50%dispersion in oil) was added in portions to a cooled, stirred mixture ofdimethylaminobenzaldehyde (16.7 g.) and ethyl acetate (200 ml.). Afterstanding overnight, glacial acetic acid was added and excess of ethylacetate was distilled off in vacuo. The residue was triturated withwater, filtered off, dried and crystallized from light petroleum to givethe desired compound as a yellow crystalline solid, M.P. 7072 C. Yield12 g.

EXAMPLE 4 Isobutyl p-dimethylamino-cinnamate Sodium hydride (33 g. of a50% dispersion in oil) was added in portions to a cooled, stirredmixture of dimethylamino-benzaldehyde (18 g.) and isobutyl acetate (400ml.). After standing overnight, glacial acetic acid (42 g.) was addedand excess of isobutyl acetate was distilled off in vacuo. The residuewas triturated with water, filtered oft, dried and crystallized fromlight petroleum to give the desired compound as pale yellow crystals,M.P. 60-63 C. Yield 63 g.

Found: C, 72.8%; H, 8.6%; N, 5.6%. C H O N requires: C, 72.8%; H, 8.4%;N, 5.7%.

EXAMPLE 5 Triethanolamine p-dimethylamino-cinnamateP-Dimethylamino-cinnamic acid (3.8 g.) and triethanolamine (3 g.) wereheated together on the steam bath until a homogeneous melt was obtainedand was then allowed to cool. The solidified melt was crystallized fromethyl acetate to give the desired product as a yellow waxy solid, M.P.l29134 C.

EXAMPLE 6 Di-isobutyl p-dimethylamino-benzalmalonate A solution ofp-dimethylamino-benzaldehyde (10.5 g.), piperidine (1 ml.), benzoic acid(0.3 g.) and di-isobutyl malonate (9.4 g.) in dry benzene (50 ml.) washeated under reflux at 130140 C. until no more water could be separatedout from the refluxing distillate by means of a Dean & Starke phaseseparator associated with the reflux column. On cooling the desiredcompound crystallized. Yield (on recrystallization from ethanol) 14.8 g.of crystals, M.P. 99100 C.

Found: C, 69.2%; H, 8.4% N, 4.3%. C H O N reuires: C, 69.1%; H, 8.4%; N,4.0%.

EXAMPLE 7 Blackout lotion Isopropyl myristate (98 g.) and diethylp-dimethylamino-benzalmalonate (0.5 g.) were warmed at 50 C. to effectsolution of the latter. 2-ethoxyethyl p-methoxycinnamate (0.5 g.) wasadded and the resulting mixture was cooled to room temperature.

8 EXAMPLE 8 Blackout lotion Ingredient: Amount, grams (1) Cetyl alcohol0.5 (2) Stearic acid 3.0 (3) Lanolin 0.5 (4) Mineral oil 5.0 (5)Preservative 0.2 (6) Z-ethoxyethyl p-rnethoxy-cinnamate 2.0 (7) Diethylp-dimethylamino-benzalmalonate 2.0 (8) Triethanolamine 3.0 (9) Glycerine3.0 (10) Distilled water 83.3

Ingredients 1 to 7 were mixed together and heated to 95 C., thistemperature being maintained until the mixture was homogeneous. Themixture was then cooled to 70 C.

Ingredients 8 to 10 were heated to 70 C. and were then added withstirring to the mixture of ingredients 1 to 7 while the mixture cooledto 35 C. The resulting mixture was then allowed to stand overnight toform the desired blackout loation.

EXAMPLE 9 Blackout cream Ingredient: Amount, grams (1) Mineral oil 5.0(2) Lanolin 0.5 (3) Polyoxyethylene lanolin derivative (Solulan 98 3.0(4) Glyceryl monostearate S.E. (self-emulsifying) 5 .0 (5) Stearic acid15.0 (6) Preservative 0.2 (7) 2-ethoxyethyl p-me'thoxycinnamate 2.0 (8)Diethyl p-diniethylaminobenzalmalonate 2.0 (9) Propylene glycol 5.0

(10) Distilled water 62.3

Ingredients 1 to 8 were homogenised at C. Ingredients 9 and 10 wereheated to 80 C. and added to the mixture of ingredients 1 to 8 at thistemperature with mechanical stirring while cooling to 35 C. Theresulting product was immediately packed in jars.

EXAMPLE 10 Blackout lotion Ingredients 1 to 8 were homogenised at 80 C.Ingredients 9 and 10 were heated to 80 C. and added to the mixture ofingredients 1 to 8 at this temperature with mechanical stirring whilecooling to 35 C. The resulting cream was immediately packed in jars.

In the foregoing Examples 7 to 10, the primary sunscreening compound maybe replaced by another compound according to the invention having acomparable ultraviolet absorption spectrum and the 2-ethoxyethylp-methoxycinnamate may likewise be replaced by a comparable knownsunscreening agent.

The terms blackout loation and blockout cream employed in Examples 7 and10 are used as referring to the absorption not only of the burning rangeof the ultraviolet portion of the spectrum, but also of that portionwhich in the case of normal white persons is regarded as the tanningrange. The lotions and creams exemplified are illustrative of the manyforms which the compositions of the invention may take; the lotions andcream can be employed in the same fashion as conventional lotions andcreams.

We claim:

1. Triethanolamine p-dimethylamino-cinnamate.

2. A dermatologically acceptable liquid or semi-liquid carrier havingtherein from 0.5 to 10% by weight of at least one dermatologicallyacceptable ultraviolet absorbing compound of the formula:

\N@CH=C/ Rf w wherein W represents hydrogen or COZ; Y and Z, which maybe the same or different, each represent R where R is hydrogen, alkyl offrom 1 to 4 carbons or represent 0B where B is a dermatologicallyacceptable group selected from alkali metal, ammonium and substitutedammonium; and R and R which may be the same or different, each representalkyl of from 1 to 4 carbons, said composition being such as to form ontopical application a continuous film or coating on the skin, andwherein there is also present in the composition an effective amount ofat least one other dermatologically acceptable ultraviolet absorbingcompound which is effective at a wavelength between 290 and 320 mu.

3. A composition as claimed in claim 2 wherein the dermatologicallyacceptable compounds are present in a molar ratio of one compound to theother of from 1:10 to :1.

4. Method of protecting the skin against erythemaproducing or otherundesired ultraviolet radiation, which comprises applying to the skin afilm or coating of a composition comprising a cosmetic carrier havingdisseminated therethrough an effective proportion of at least onedermatologically acceptable ultraviolet absorbing compound of theformula:

COY

wherein W represents hydrogen or COZ; Y and Z, which may be the same ordifferent, each represent 0R Where R is hydrogen, alkyl of from 1 to 4carbons or represent OB where B is a dermatologically acceptable groupselected from alkali metal, ammonium and substituted ammonium; and R andR which may be the same or different, each represent alkyl of from 1 to4 carbons.

5. A dermatologically acceptable liquid or semi-liquid carrier havingtherein an effective amount of the dermatologically acceptableultraviolet absorbing compound triethanolamine p-dimethylaminocinnamatewhich forms on topical application a continuous film or coating on theskin.

6. Method of protecting the skin against erythemaproducing or otherundesired ultraviolet radiation, which comprises applying to the skin afilm or coating of a composition comprising a cosmetic carrier havingdisseminated therethrough an effective proportion of diethylp-dimethylaminobenzalmalonate.

7. Method of protecting the skin against erythema-producing or otherundesired ultraviolet radiation, which comprises applying to the skin afilm or coating of a composition comprising a cosmetic carrier havingdisseminated therethrough an effective proportion of triethanolaminep-dimethylaminocinnamate.

8. Method of protecting the skin against erythemaproducing or otherundesired ultraviolet radiation, which comprises applying to the skin afilm or coating of a composition comprising a cosmetic carrier havingdisseminated therethrough an effective proportion ofp-dimethylamino-cinnamic acid.

9. Method of protecting the skin against erythemaproducing or otherundesired ultraviolet radiation, which comprises applying to the skin afilm or coating of a composition comprising a cosmetic carrier havingdisseminated therethrough an effective proportion of di-isobutylp-dimethylamino-benzalmalonate.

10. Method of protecting the skin against erythemaproducing or otherundesired ultraviolet radiation, which comprises applying to the skin afilm or coating of a composition comprising a cosmetic carrier havingdissemintaed therethrough an effective proportion of isobutylp-dimethylamino-cinnamate.

11. Method of protecting the skin against erythemaproducing or otherundesired ultraviolet radiation, which comprises applying to the skin afilm or coating of a composition comprising a cosmetic carrier havingdisseminated therethrough an effective proportion of ethylpdimethylamino-cinnamate.

12. Method of protecting the skin against erythemapound of the formula:

0 OY R1 CH= wherein W represents hydrogen or COZ, Y and Z, which may bethe same or different, each represent 0R where R is hydrogen, alkyl offrom 1 to 4 carbons or represent OB where B is a dermatologicallyacceptable group selected from alkali metal, ammonium and substitutedammonium and R and R which may be the same or different, each representalkyl of from 1 to 4 carbons and wherein there is also present in thecomposition at least one other dermatologically acceptable ultravioletabsorbing compound which exerts effective absorption of ultravioletlight at a wavelength between 290 and 320 mg.

13. Method of protecting the skin. against erythemaproducing or otherundesired ultraviolet radiation, which comprises applying to the skin afilm or coating of a composition comprising a cosmetic carrier havingdisseminated therethrough an effective proportion of at least onedermatologically acceptable ultraviolet absorbing compound of theformula:

wherein Y is CR where R is alkyl of from 1 to 4 carbons and R and Rwhich may be the same or different, each represent alkyl of from 1 to 4carbons and the salts thereof selected from the group consisting ofalkali metal, ammonium and substituted ammonium.

14. Method of protecting the skin against erythemaproducing or otherundesired ultraviolet radiation, which comprises applying to the skin afilm or coating of a composition comprising a cosmetic carrier havingdisseminatedtherethrough an effective proportion of at least onedermatologically acceptable ultraviolet absorbing of the formula:

COZ

COY

(References on following page) 1 l 12 References Cited Chem. Abst., vol.55, col. 16468h (1961). AbSt., V01. CO1. (August 2,798,881 7/1957 Baer@t 260471 ALBERT T. MEYERS, Primary Examiner.

O H REFERENCES 5 JULIAN S. LEVITT, S. ROSEN, Examiners.

Journal of the Amer. Chem. Soc., vol. 82, pp. 1907-11 CLARKE, Assistantxa i (1960).

Zabicky, Journal Chem. Soc. (London), 1961, pp. 683- 687, Chem. Abst,V01. 55, CO1. 5410g (1961).

4. METHOD OF PROTECTING THE SKIN AGAINST ERYTHEMAPRODUCING OR OTHERUNDESIRED ULTRAVIOLET RADIATION, WHICH COMPRISES APPLYING TO THE SKIN AFILM OR COATING OF A COMPOSITION COMPRISING A COSMETIC CARRIER HAVINGDISSEMINATED THERETHROUGH AN EFFECTIVE PROPORTION OF AT LEAST ONEDERMATOLOGICALLY ACCEPTABLE ULTRAVIOLET ABSORBING COMPOUND OF THEFORMULA: